Single Phase Induction Motors Working Principle: Single Phase Induction Motors Working Principle are inferior in performance and lager in weight and volume compared to three-phase motors of the same rating. However, they are simple, robust, reliable and less expensive for small ratings. They are employed in low power drives in small industries and domestic and […]
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Pole Amplitude Modulation Induction Motor: Pole changing method as already discussed allows a change of speed by a factor 2. In some applications, speed change is required only by a small amount, e.g. some fan and pump drives require speed reduction to reduce power output at the most to half of rated. Since, torque is
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Dynamic Braking of Induction Motor(or Rheostatic Braking): (a) AC Dynamic Braking – AC Dynamic Braking of Induction Motor is obtained when the motor is run on a single phase supply by disconnecting one phase from the source and either leaving it open (Fig. 6.15(b)) or connecting it with another machine phase (Fig. 6.15(c)). The two
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Ward Leonard Method of Speed Control: Known after the name of its inventor Ward Leonard Method of Speed Control (1891), it consists of a separately excited generator feeding the dc motor to be controlled. The generator is driven at a constant speed by an ac motor connected to 50 Hz ac mains. The driving motor
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Types of DC Motor: The commonly used Types of DC Motor are shown in Fig. 5.1. In a separately excited motor, the field and armature voltages can be controlled independent of each other. In a shunt motor, field and armature are connected to a common source. In case of a series motor, field current is
Synchronous Machine: Armature Reaction in Synchronous Machine : By using Simple circuit model of the synchronous machine was obtained by making the assumption that the magnetic circuit … Brushless DC Motor Working Principle : The term Brushless DC Motor Working Principle is applied to many configurations of ac synchronous motors in which semiconductor … Capability
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Rotating Machines: 2 Pole DC Machine : Figure 5.13 shows a 2 Pole DC Machine Diagram with a single coil rotating armature. It may … Current sheet Concept : Current sheet Concept – It was seen above that a distributed winding gives rise to a stepped mmf … DC Machine Armature Winding : With reference
Starting Methods of Synchronous Motor for LCI: It has been pointed out that a Starting Methods of Synchronous Motor for LCI, even though complicated in its construction, has an advantage that it can provide the necessary reactive power required by the inverter, except at low speed. Among all the drives possible with synchronous motor, Starting
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Synchronous Speed on Variable Frequency Supply: As has already been discussed, the speed of a synchronous motor can be varied by supply frequency variation similar to an induction motor. The applied voltage must be varied in this case also to have the maximum torque capability and to avoid saturation at all frequencies. A Synchronous Speed
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Synchronous Motor Drives: Variable frequency drives employing synchronous motor are receiving considerable interest, and are even becoming competitors to both induction motors and dc motors. These are popular as drives for very high power applications, such as pumps, fans, conveyors, etc. The stator of the synchronous motor is supplied from a thyristor power converter capable
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